Workplace Safety and Insurance
Appeals Tribunal

Established in 1985, the Workplace Safety and Insurance Appeals Tribunal (WSIAT) is the final level of appeal to which workers and employers may bring disputes concerning
workplace safety and insurance matters in Ontario. WSIAT has always been separate from and independent of the
Workplace Safety and Insurance Board.

Highlights of Noteworthy Decisions

Decision 665 10 I2

7/30/2013

M. Keil - S. Sahay - J. Crocker

Causation (thin skull doctrine)

Charter of Rights

Stress, mental (standard of proof)

In Decision No. 665/10I, the Panel found that the worker did not have entitlement for acute mental stress arising from an incident in October 2005. The worker then pursued a Charter challenge regarding s. 13(4) and (5) of the WSIA. As part of the consideration of the Charter challenge, the Panel now considered whether the worker would have succeeded on the appeal if not for s. 13(4) and (5).The issue of whether the worker's stress case would have succeeded in the absence of the limitations imposed by s. 13(4) and (5), and applicable Board policy, in turn raises the question of whether the "average worker" test should apply. The majority of Tribunal decisions have adopted the average worker test. The test is framed as follows in Decision No. 422/96: 1) whether it is reasonable that workers of average mental stability would perceive the workplace events to be mentally stressful; 2) if so, would such average workers be at risk of suffering a mental reaction to such perceptions.Tribunal decisions have justified the average worker test on the basis that it assists in identifying whether there is a work-related injuring process. The Panel found it helpful to consider a "mental/mental" case in the manner that it would approach a disablement case. In general, a panel would not ask in a disablement case whether the average person would have incurred an injury working in a certain job. Rather, the panel would come to a decision based on the specific evidence, such as the nature of the job, the mechanical factors, length of time performing the job, any recent changes in the job or workload, external factors, medical opinions and testimony of the worker. The Tribunal does not apply an average worker test to physical disablement cases. There is consideration of whether the work is objectively repetitive or stressful, but that consideration is located in the nature of the work and not in how an average worker perceives or experiences the work.The Panel found that a worker's belief is not determinative of causation in reference to either a psychological or an organic injury. To the extent that the average worker test suggests only that objective and good evidence need be present in order to grant entitlement, it may provide a useful guide. However, to the extent that it is used rigorously and mechanically, it is not a useful adjudicative tool.The Panel also considered use of the term "average mental stability" and found that it introduced an unnecessary filter and that, if applied strictly, it could conflict with the thin skull doctrine, and cannot be legally justified. The rigour and objectivity of adjudication lies in obtaining all relevant facts, testing of testimony against known facts and weighing of evidence. This rigour can be applied to all cases. Such rigour cannot lie in a different threshold to entitlement for chronic stress cases, as opposed to organic repetitive strain injuries.The Panel went on to emphasize three points: 1) it is not necessary to consider an average worker in order to determine in any particular case whether an injuring process arose out of employment; 2) credibility is assessed not by labelling a person of average mental stability but, rather, by considering the testimony in the context of the facts; 3) the average worker test is untenable to the extent that it comes into conflict with the thin skull doctrine.In this case, the Panel found that the worker was employed in an objectively stressful environment for many years, working with children at risk and later choosing suitable foster parents for those children. There was an increasing number of children needing placement without corresponding increase in staffing levels. The Panel also considered the medical opinions and the worker's testimony. It was not necessary to consider an average worker test to find that, but for the exclusionary provisions of s. 13(4) and (5), the worker would have had entitlement.The hearing will reconvene to hear the Charter issue.